Legal basement apartments in Toronto, designed to meet the Building Code.

Yes. Toronto Building issues a building permit for an interior alteration that adds a second dwelling unit to a detached house, semi or townhouse; its guide names the basement apartment as the common example. The application needs a site plan referenced to your survey with a zoning summary, fully dimensioned floor plans of every level showing smoke and CO alarm locations and plumbing fixtures, sections with floor-to-ceiling heights and stair details, construction details, the Application to Construct or Demolish, Schedule 1 Designer Information and the Rental Renovation Licence Screening Form, all as PDFs through Toronto Building's online Application Submission Tool. Building without a permit adds 50% of the permit fee or $214.79, whichever is greater, up to $29,456.99.

Across Toronto's residential zones, yes, as-of-right (allowed without a rezoning or minor variance): By-law 569-2013 permits one secondary suite per dwelling unit in a detached house, semi-detached house or townhouse (Chapter 150.10, By-law 549-2019). In the apartment, commercial, commercial-residential and institutional zones (RA, RAC, CL, CR, I and others) the suite must sit inside a lawfully existing house of one of those three types. The suite is capped at 45% of the dwelling unit's interior floor area, except in a one-storey detached house, where it may take the whole basement. No parking space is required for it. The zoning review with your quote confirms your zone and the area split.

Toronto's Property Standards by-law sets 1.95 m over at least half the floor area as the minimum for a habitable room, and bars any basement from use as a dwelling unit unless every habitable room meets the rules for ceiling height, a way out (egress), light and ventilation (Chapter 629, § 629-4 and § 629-25). Measure to the underside of the joists, then under the beams and ducts, which often set the real number. Below 1.95 m the floor is lowered and the footings underpinned: a Professional Engineer designs and reviews the work where the new footing sits below a neighbour's footing within the soil's angle of repose (close enough to it that digging could undermine it), and the City requires engineer testing at the first and last stages in every case. The City's underpinning fee is $12.37 per linear metre (2026). The Building Code's own rules for the renovation are applied in the permit review; we design to both.

It needs its own way out to ground level. Toronto Fire Services lists three exit problems it finds in two-unit houses: no dedicated exterior door leading directly to ground level, a shared route through the other unit, and an exit that does not lead directly outdoors. A new below-grade entrance is a permit item in its own right: the City's basement-entrance guide asks for a site plan with setbacks, foundation plans with the underpinning stages numbered and the distance to the neighbour's footings, and sections showing the grade height above the basement floor and the landing at the base of the stair. Where the new footing goes below an adjacent footing within the angle of repose, a Professional Engineer designs it. We draw the entrance, the stair, guards and handrails, and coordinate the engineer.

Toronto Building requires the floor plans to show the location of every smoke alarm and CO alarm, and Toronto Fire Services names the lack of interconnected alarms throughout the house as a risk factor in two-unit homes, so the set lays out interconnected alarms on both levels. For CO: in a house with two units an alarm is required in a suite with a fuel-burning appliance or fireplace, in one that sits above, below or beside a service room with such an appliance or beside a garage, and, since January 1, 2026, in one heated by air from a fuel-burning appliance elsewhere in the house. They go adjacent to each sleeping area and, since January 1, 2026, on every storey of the suite, plus one in the service room itself. Hardwired, battery and plug-in units are all permitted under the Fire Code.

Toronto Building's 2026 rate for interior alterations is $11.53 per m² of altered floor area, plus a residential unit fee of $56.33 for the new unit, with a minimum permit fee of $214.79 for any work. A 70 m² suite is $807.10 plus $56.33, or $863.43 in all. Underpinning, if the floor is lowered, is $12.37 per linear metre. Plumbing and HVAC permits are applied for alongside and charged separately. All of this is paid to the City at submission and is separate from our fee.

Two things. The permit application includes the City's Rental Renovation Licence Screening Form, which checks whether the City's rental renovation licence by-law (Chapter 662) applies. Since July 31, 2025, a landlord who serves an N13 notice (the Ontario form that ends a tenancy for renovations) because the work needs the unit vacant must hold a Rental Renovation Licence for that unit: apply within seven days of the notice with the building permit already issued, pay $728 per unit (2026), post the City's Tenant Information Notice on the door, and provide either comparable temporary housing or rent-gap payments, plus a $1,500 or $2,500 moving allowance. Work that can be done without an N13 needs no licence. The building permit comes first, which is the order the by-law requires.

Architalcan's office prepares the drawings, and they are signed under BCIN 25897 – 41741 (House, Small Buildings, Large Buildings, HVAC-House). Toronto Building requires drawings prepared by a qualified designer to carry the designer's name, registration number, qualification number, signature and a statement accepting responsibility for the design; ours do. Sheets that need an engineer carry the engineer's seal; underpinning or structural sheets sealed by a Professional Engineer are filed with the Assumption of Responsibility for Engineering Content form and, where the City requires field review, the Commitment to General Reviews.